Examine the relationship between IGFs action to increase forearm blood flow and its metabolic effects. After baseline measurements, Insulin-like growth factor 1(IGF-1) will be coinfused intraarterially with NG-monomethyl-L-arginine(L-NMMA) in one arm, and L-NMMA alone in the other arm. In a separate study, Nitroprusside will be infused intraarterially in one arm, and L-NMMA will be infused in the other. Repeat measurements will be made after 3 and 6 hours of the infusions.